We have spent the past few days talking to neuroscientists, and asking them, essentially, whether they are losing their minds.

The reason is a wee statement that appears in a scholarly paper published in the April edition of the British Journal of Sports Medicine, a study that asks the most imperative question of this sporting era: What is the current state of evidence for chronic traumatic encephalopathy, or CTE, in retired athletes?

And in their conclusion, the people who are responsible for this seminal study summarized the findings from their December conference in Zurich with this whopper:

They're saying that all these boxers and footballers and hockey players -- former world-class athletes whose lives have been devastated by dementia -- could just as easily have been impaired by. . . junk food, perhaps? Reality TV? Pet dander?

And to think, we were under the impression that CTE resulted from repeated head trauma.

Our mistake. Call us alarmists. That epidemic of NFL stars shooting bullets into their own hearts is just an anomaly, apparently.

We don't mean to be glib about a serious subject, but it eludes you. In fact, it also eludes some of the smartest people we know.

"When I saw in the consensus statement that we need more data in terms of CTE, I wrote to the other authors, in essence, 'What the hell do you mean that we need more data?'" Dr. Robert Cantu said in a phone conversation Thursday. "The whole breadth of the document is large, and 99 percent of it it I strongly support. But that part of it, I don't support at all. Frankly, it stunned me."

We should point out that Dr. Cantu, arguably our country's foremost authority on concussions, was actually on the writing committee that authored this paper in Zurich.

The paper's conclusion, obviously, sounds counterintuitive. So when it was brought to our attention, we rang Cantu and two other neurologists who participated in the Zurich conference – world-class scientists whose research was used in the paper itself.

And all three brain specialists are in agreement over one thing: Ever since terms "punch drunk" and "dementia pugilistica" were first applied to boxers back in 1928, every shred of research links CTE – the progressive, neuro-degenerative disease that has symptoms similar to Alzheimers – with concussions.

It is an inarguable point for someone who has done as much research as Cantu, or his Boston University colleague, Dr. Ann McKee. Her befuddlement, even when typed, is obvious:

"This is a time that calls for immediate action to reduce the amount of head trauma experienced by athletes in all sports to prevent CTE," McKee said via email. "And it is now irresponsible to justify inaction by requesting a level of scientific proof that will take decades to acquire."

And that's perhaps the core issue here.

This paper has already been disseminated throughout the world and will soon be the protocol on treating concussions for those who govern professional and amateur sports. To suggest (irresponsibly, to use Dr. McKee's term) that CTE "may not be part of the impact exposure, but rather due to other yet unidentified factors" – such as age, alcohol abuse, mental illness – could give tacit permission to those who play collision sports to proceed as if there is no urgent problem when concussions arise.

It wasn't intended to have such an implication, says Dr. Rosemarie Moser, the Lawrenceville neuropsychologist whom we often turn to talk us off the ledge.

"Keep in mind that the conclusion was worded for the scientific community," Moser said. "Also, the Zurich conference was not just about American football. Americans are ahead of the game in terms of concussion knowledge, but (outside) perceptions are that we are jumping to conclusions if we say, 'If you play football, you're probably going to get CTE.' Which is not the case. So what differentiates those with CTE from those who don't have it? That's what we need to know."

But to perform such a controlled study with a representative sample -- one that would satisfy the international scientific community -- would take decades.

"It would take 50 years to do double-blinded prospective study," said Cantu, referring to an experiment in which a researcher is kept ignorant of the subject's athletic background, so as to not prejudice the result.

Until then, this report from the world's leading neurologists officially says that the evidence isn't in, and that "interpretation of causation in the modern CTE case studies should proceed cautiously."

You wonder whether someone like Roger Goodell thinks we should wait until all the evidence is in, before taking responsible action.

The day this study was posted on the BJSM website, the commissioner was in Chapel Hill, N.C., where he called for a culture of safety in his league. "Scientists and doctors know more about concussions than they did even a few years ago," Goodell said. "This is our biggest challenge: changing the culture to reduce injury risk, especially head injury."

Someday soon, his league will be brought to court by more than 3,800 former players, who will allege that the NFL ignored the link between repeated blows to the head and brain damage -- even after CTE was found in those brains examined by people like Cantu and McKee.

And when the lawyers start talking, the game will quickly change from football to hardball.

"I'm very interested on how this report will affect the NFL players' lawsuit," Moser said. "I think it could influence it in a very controversial way."

"This report is going to be a very highly-cited source, unquestionably, in the lawsuits," Cantu agreed. "Everyone will hang on to the notion that we don't have Class 1 evidence – and technically, we don't.

"But we do have case after case after case that stretches back 80 years. And the expectation, at least to me, is that the line in the consensus summary is going to come back to bite this group."